type 'a conv = t -> 'a optionA converter from S-expressions to 'a is a function sexp -> 'a option.
Map over a list, failing as soon as the function fails on any element
list_any f (List l) tries f x for every element x in List l, and returns the first non-None result (if any).
list_all f (List l) returns the list of all y such that x in l and f x = Some y
val to_int : int convExpect an integer
val to_string : string convExpect a string (an atom)
val to_bool : bool convExpect a boolean
val to_float : float convExpect a float
Expect a list, applies f to all the elements of the list, and succeeds only if f succeeded on every element
Same as to_pair but applies conversion functions
get_field name e, when e = List [(n1,x1); (n2,x2) ... ], extracts the xi such that name = ni, if it can find it.
get_variant l e checks whether e = List (Atom s :: args), and if some pair of l is s, f. In this case, it calls f args and returns its result, otherwise it returns None.
field_list name f "(... (name a b c d) ...record)" will look for a field based on the given name, and expect it to have a list of arguments dealt with by f (here, "a b c d").